add docs to make clippy extra happy

crates/derive/keyfork-derive-openpgp/src/lib.rs

@@ -19,8 +19,14 @@ use sequoia_openpgp::{
     Cert, Packet,
 };
 
+// TODO: this key type is actually _not_ the extended private key, so it should be renamed
+// something like Prv or PrvKey.
+
+/// The private key type used with OpenPGP.
 pub type XPrvKey = SigningKey;
-pub type XPrv = ExtendedPrivateKey<SigningKey>;
+
+/// The extended private key type used with OpenPGP.
+pub type XPrv = ExtendedPrivateKey<XPrvKey>;
 
 /// An error occurred while creating an OpenPGP key.
 #[derive(Debug, thiserror::Error)]

crates/derive/keyfork-derive-path-data/src/lib.rs

@@ -6,6 +6,7 @@ use once_cell::sync::Lazy;
 
 use keyfork_derive_util::{DerivationIndex, DerivationPath};
 
+/// All common paths for key derivation.
 pub mod paths {
     use super::*;
 

crates/qrcode/keyfork-qrcode/src/lib.rs

@@ -103,6 +103,11 @@ pub fn qrencode(
 const VIDEO_FORMAT_READ_ERROR: &str = "Failed to read video device format";
 
 /// Continuously scan the `index`-th camera for a QR code.
+///
+/// # Errors
+///
+/// The function may return an error if the hardware is unable to scan video or if an image could
+/// not be decoded.
 #[cfg(feature = "decode-backend-rqrr")]
 pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QRCodeScanError> {
     let device = Device::new(index)?;
@@ -133,6 +138,11 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
 }
 
 /// Continuously scan the `index`-th camera for a QR code.
+///
+/// # Errors
+///
+/// The function may return an error if the hardware is unable to scan video or if an image could
+/// not be decoded.
 #[cfg(feature = "decode-backend-zbar")]
 pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QRCodeScanError> {
     let device = Device::new(index)?;